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In this study, Zr₅₅Cu₃₀Al₁₀Ni₅ bulk metallic glass (BMG) and pure copper plates were successfully joined by friction stir butt welding, friction stir lap welding and friction stir spot welding, respectively. Microstructure characterization by OM, EBSD and TEM revealed that a clear interface between the two materials was formed in the butt welded joint and no crystallization from the amorphous phase can be detected. However, mixing area containing bulk metallic glass blocks and copper can be observed in the stirred region for the friction stir lap welded joints and friction stir spot welded joints. Crystallization of the BMGs after welding was also found in the stirred region for the friction stir spot welded joints. Tensile tests of the BMG/Cu joints show that the all the joints shows strong bonding at the interface but exhibit different deformation behaviour depending on the different welding technique. The butt welded joints fractured in the copper side close to the BMG/Cu interface. While the lap welded joints fractured in the BMG plate with the BMG/Cu interface undamaged after tensile tests. For the spot welded joint, the fracture start in the copper plate at the edge of the stir zone and finally split from the BMG plates. The microstructure dependent deformation mechanism was investigated and discussed.

8th International Symposium, 18-20 May 2010, Poster Session, Paper 07